From time immemorial, the world of education has been a crucible for polarised opinion and acrimonious debate.

OPINION:
More often than not, such debate has produced more heat than light, cleaving protagonists and antagonists into irreconcilable and bitterly warring factions.

Most recently in New Zealand, there has been a vitriolic public outcry over class sizes, national standards and the prospect of so-called ''league tables'', a cliche that has its origins in the historic four divisions of the English Football League.

Fine if your team is Chelsea, Manchester United, Arsenal or Liverpool, but not quite so affirming for the ego if you happen to be a supporter of Accrington Stanley, Port Vale, Rotherham or Plymouth Argyle.

Advocates of league tables contend that parents and the community should be informed where one school rates in comparison to another. Such competition, the argument goes, will encourage schools, like football clubs, to improve their performance and lift the standard of New Zealand's educational offering.

I may be wrong, but I sense such reasoning is linked to an assumption that the quality of teaching is pretty ordinary, and that this new-fangled approach will engender a long-overdue improvement in teacher performance.

"Could do better", of course, is an emotive phrase often applied liberally by armchair critics to the teaching profession in New Zealand as a whole.

For it to assume any real meaning, there needs to be an explicit comparison of New Zealand's educational outcomes with other countries, particularly those in the OECD.

The PISA (Programme for International Student Achievement) rankings, therefore, which compare national performance in reading, science and mathematics, provide a credible and widely accepted ''league table'' to which we should pay close attention. Conducted by the OECD, they represent an objective measure of our educational success in comparison with that of other so-called developed and developing countries and, by implication, are indicative of the effectiveness of our teaching profession in New Zealand. A close perusal of the 2009 results provides some interesting food for thought.

In reading, New Zealand students rate seventh out of 74. Above us are five Asian countries or regions: Shanghai-China, Singapore, Hong Kong-China, Japan and South Korea. The only Western-Hemisphere country to rank above us is Finland. Below us are such countries as Canada, Australia, Britain, the United States, France, Germany and Sweden. By any reckoning, the performance of New Zealand is in the top echelon.

Our performance in science is equally outstanding. Once again, our students rank seventh behind four of the top performing Asian countries or regions (Shanghai-China, South Korea, Hong Kong-China, Singapore) and narrowly behind Finland and Canada of the Western Hemisphere. As with our results in reading, we rank above Australia, Germany, France, Britain, the United States, Switzerland and Sweden.

In mathematics our performance is a little lower at 13th. Here, we are headed by the similar group of Asian countries including Shanghai-China, Singapore, Hong Kong-China, Chinese-Taipei, Macau-China and Japan. From the Western Bloc, we are shaded by Finland, Liechtenstein, Switzerland, the Netherlands and Canada. Notwithstanding this slightly lower ranking in mathematics, we still perform above Australia, Germany, France, Britain, the United States and Sweden.

Can we ''do better'' in New Zealand? I am sure that we can. But any criticism of our education standards needs to be evaluated in a global context. Several of the ''Asian Tigers'' do feature above us, but at what cost to the overall development of their students? At the risk of generalising, the pedagogical approach adopted in those countries tends to be highly teacher-centred and pressure-cookered, the very antithesis of the inquiry model promoted rigorously by the Education Ministry.

I suspect that a wholesale return to highly formalised, rote-learning, structured teaching methodology would have very limited appeal to students, parents and teachers in New Zealand. Of the Western countries, Finland is often lauded as the zenith of educational achievement, a country where teaching as a profession is regarded highly and a model to which all should aspire. It is unarguable that Finland does produce stellar academic results, but a closer scrutiny of its demographic components is revealing.

Only 3.4 per cent of its population is composed of foreign citizens, one of the lowest figures in the European Union. Most of these are from Russia, Estonia and Sweden. Finland's indigenous minority consists of only 7000 Sami, the small group who inhabit the icy wastes to the north of the country. In short, Finland is perhaps the most homogeneous country in Europe, without many of the educational challenges that arise with either mass migration or the integration of large indigenous minorities.

Where does that leave our education system in New Zealand? On the surface, our overall performance is quite outstanding.

However, there is widespread criticism that the performance of our "bottom 20 per cent" is very poor and a blight on the system.

Simple logic, surely, would imply only two possible causes for that.

On the one hand, New Zealand teachers who perform outstandingly well with the top 80 per cent of our students for some inexplicable reason may be abysmally poor in teaching the bottom 20 per cent. This could be true, but I have my doubts.

On the other hand, the performance of the bottom 20 per cent of our students may reflect a disturbing demographic reality in our country that has been exacerbated in recent decades, and is not reflected in countries such as Finland. Intergenerational unemployment, a widening gap between the haves and have-nots, the challenges of redress for Maori, and the integration of new immigrants to our country are all major challenges that our country is facing. Inadequate teaching, I would suggest, is not the cause of these deep-seated issues, any more than inspired teaching can be the sole panacea.

More effective teaching of disengaged students must be part of the long-term solution if positive change is to occur. In the process, however, let us not ignore the fact that New Zealand teachers are doing a fine job and that they, alone, cannot right the deep-seated inequalities in our society.